[Fwd: Re: Audi 100 Won't Start]

Huw Powell audi at humanspeakers.com
Mon Jan 26 20:54:52 EST 2004

> I too am thinking about the possibility of a vacuum leak in fact today I 
> was trying to check the hose that runs from the ISV to the rubber air 
> bonnet.  I've checked all the visible hoses but its really difficult to 
> check since car won't run for that long.  Any tips finding a vacuum 
> leak?  It would (in my view) have to be a very large leak to prevent the 
> car running.  I've disconnected small hoses  before without it shutting 
> off the car.

Disconnecting hoses on a running car is different - it's warm, and the 
closed loop ECU can compensate.

Your car isn't starting properly, although I guess it does "catch" a bit.

Anyway... you should literally be able to pull a vacuum on the intake 
tract, I think.  Any open intake valve will lead to a closed exhaust 
valve.  Only trouble is stopping air from coming in through the "normal" 
inlet - might be easy to block, at least, if it's me saying and you 
doing it, I call that "easy"...

Hook up a mity-vac or something and play.  Also, blowing compressed air 
in (just a few psi) might find something.

Huw Powell



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